1. Field of the Invention
The inventions disclosed and taught herein relate generally to earth boring drill bits; and more specifically relate to hybrid PDC/roller cone earth boring drill bits.
2. Description of the Related Art
U.S. Pat. No. 4,343,371 discloses a “hybrid rock bit . . . wherein a pair of opposing extended nozzle drag bit legs are positioned adjacent a pair of opposed tungsten carbide roller cones. The extended nozzle face nearest the hole bottom has a multiplicity of diamond inserts mounted therein. The diamond inserts are strategically positioned to remove the ridges between the kerf rows in the hole bottom formed by the inserts in the roller cones.”
U.S. Pat. No. 7,398,837 discloses a “drill bit assembly [that] has a body portion intermediate a shank portion and a working portion. The working portion has at least one cutting element. In some embodiments, the drill bit assembly has a shaft with an end substantially coaxial to a central axis of the assembly. The end of the shaft substantially protrudes from the working portion, and at least one downhole logging device is disposed within or in communication with the shaft.”
U.S. Pat. No. 7,350,568 discloses a “method for logging a well. Includes receiving energy with at least one array of elements coupled to a drill bit, wherein the at least one array of elements functions as an electronic array. An apparatus for logging a well includes a drill bit and at least one array of elements coupled to the drill bit, wherein the at least one array of elements functions as an electronic array.”
The inventions disclosed and taught herein are directed to an improved hybrid PDC/roller cone earth boring drill bit.